This invention relates generally to the field of web feed devices. More specifically, the invention relates to apparatus for accelerating a first web of material to the velocity of a moving second web of material and finds particularly utility for joining the leading edge of a fresh web of material to the trailing edge of an expiring web of material without interrupting the continued advance of the expiring web.
There are many manufacturing operations wherein most efficient utilization of raw materials and equipment requires the manufacturing operation to be conducted on a continuously moving web. Because there is no such thing as an endless supply of raw material, particularly rolled material such as paper, cardboard, kraft, floor coverings and the like, it has been a course of continuing concern to those skilled in these arts as to the best manner in which to connect the trailing edge of one roll of material being utilized in a production process with the leading edge of a next subsequent roll of material to be utilized in the manufacturing process.
Some industries have found the problem to be incapable of being solved on an economically sound basis and have been resigned to the necessity of terminating manufacturing operations while the next succeeding roll of raw material is connected to the roll of raw material in the process of exhaustion in the apparatus.
Other industries have been able to justify equipment for splicing a fresh web to an expiring web without requiring termination of the manufacturing process. In this regard, the most oft used form of apparatus for permitting splicing without interruption of the advance of the active web through the production line is called an accumulator. Such an accumulator gathers in-feed web material, e.g. by providing a mechanically adjustable tortuous path, and stores the excess length of in-feed material until such time as it is desired to make a splice. Upon the occurrence of the time for splicing, the trailing end of the active web is clamped and the accumulator is permitted to unload its excess material thus permitting the trailing end to remain stationary while being spliced to the fresh web while at the same time permitting the operation of the production line to be maintained. As is well known by those skilled in the arts, such accumulator apparatus is expensive, difficult to maintain and often times difficult to operate.
Another approach to providing a splice with respect to moving web materials without requiring shut down of an associated production line has been to mount the rolls of fresh web material on mounting devices which are rotatable. The theory of such splicing devices which utilize rotatable web support means is that a fresh web must always be positioned on top of an expiring web during splicing. With a fresh web leading edge being always on the top position for in-feed into the apparatus, many of the problems oridinarily attendant to attempts to splice moving webs are overcome. It is well recognized in these arts, however, that the rotating web support devices are expensive and further, in many existing applications, they are incapable of use because there is insufficient room for their installation in the space available.
In this regard, it should be noted that there are numerous manufacturing facilities presently operated in the United States and other countries wherein the web material is being fed through a production line and wherein shut down of the line is required for purposes of splicing a fresh web to an expiring web. With respect to such installations, there is presently no splicing equipment available which is small enough to fit within the confines of the available space and sufficiently inexpensive to justify incorporation in existing manufacturing operations.
The present invention, therefore, addresses itself not only to novel structure for achieving a splice between two moving pieces of web material but also to providing apparatus for achieving such a splice which is capable of justifiable incorporation in presently existing equipment.